Architectural Engineering Commons^™

Measurement Of Stiffness Anisotropy In Kaolinite Using Bender Element Tests In A Floating Wall Consolidometer, X. Kang, G. C. Kang, B. Bate

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A new floating wall consolidometer-type bender element testing system was developed to study the stiffness anisotropy of clays at applied vertical stresses up to 800 kPa. One-dimensional slurry-consolidated Georgia RP-2 kaolinite samples, prepared with 0.005 and 1 mol/l NaCl solutions, were tested in this system. A floating wall design eliminated the detrimental bending moment that acts upon the horizontally installed benders as a result of soil settlement in a traditional fixed wall setup, which significantly improved the signal quality and bender reuse. Floating wall-soil interface resistance was quantified with pulling tests. Analytical equations were then derived to calculate the wall …

Distribution Of Chord Forces In Large Panelized Wood Roof Diaphragms, Weichang Pang, Chun Ni, John Lawson, Sami Pant

Architectural Engineering

Flexible wood roof diaphragms are very common in the United States, both for residential buildings and large-scale commercial buildings. Due to its simplicity, the traditional diaphragm design method is commonly used in diaphragm design, in particular for the design of diaphragms with relatively small dimensions. The traditional diaphragm design method assumes the axial chord forces developed in framing members under in-plane loading are carried only by the perimeter elements. This method has always been thought to be a conservative design method, especially when applied to large diaphragms. In recent years, the engineering community began to question the applicability of the …

Examining The Applicability Of Design Methods For Large Panelized All-Wood Roof Diaphragms Under Seismic Loading, W. Pang, S. Pant, C. Ni, John W. Lawson

Architectural Engineering

The use of flexible roof diaphragms is very common in the United States, both for residential buildings and large-scale commercial buildings. Due to its simplicity, the traditional diaphragm design method is commonly used in diaphragm design, in particular for the design of diaphragms with relatively small dimensions. The traditional diaphragm design method assumes the axial chord forces developed in framing members under in-plane loading are carried only by the perimeter elements. The traditional diaphragm design method has always been thought to be a conservative design method, especially when applied to large diaphragms. In recent years, the engineering community began to …

Numerical Framework For Seismic Collapse Assessment Of Rigid Wall-Flexible Diaphragm Structures, M. Koliou, A. Filiatrault, D.J. Kelly, John W. Lawson

Architectural Engineering

This study focuses on the development of a two dimensional (2D) simplified numerical framework of rigid wall-flexible diaphragm (RWFD) structures that can be used to validate seismic design approaches. This type of low-rise industrial buildings, which is widely used in North America, incorporates rigid in-plane concrete or masonry walls and flexible in-plane wood, steel or “hybrid” roof diaphragms. The numerical modeling is detailed enough to capture the nonlinear seismic response of RWFD buildings, but simplified enough to efficiently conduct a large number of nonlinear time-history dynamic analyses. The 2D numerical modeling framework is based on a three step sub-structuring approach …

Development Of Seismic Design Methodologies For Rigid Wall-Flexible Diaphragm Structures, John W. Lawson, D. J. Kelly, M. Koliou, A. Filiatrault

Architectural Engineering

Evidence indicates that the dynamic behavior of Rigid Wall – Flexible Diaphragm (RWFD) structures is dominated by the diaphragm’s response instead of the walls’ response, and this is a significant departure from the underlying assumptions of the widely used equivalent lateral force method in current building codes. RWFD buildings are common in North America and other parts of the world, and incorporate rigid in-plane concrete or masonry walls and flexible in-plane wood or steel roof diaphragms. With the use of a numerical computer modeling framework developed specifically for this type of building, this study sets out to investigate the seismic …

The Quest For An Unambiguous Parameterization Of Mixing Efficiency In Stably Stratified Geophysical Flows, Benjamin D. Mater, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Estimates of turbulent mixing in geophysical settings typically depend on the efficiency at which shear-driven turbulence mixes density across isopycnals. To date, however, no unifying parameterization of diapycnal mixing efficiency exists due to the variability of natural flows and also due to certain ambiguities that arise from descriptions based on a single parameter. Here we highlight important ambiguities of some common single-parameter schemes in the context of a multiparameter framework that considers the independent effects of shear, buoyancy, and viscosity. Parameterizations based on the gradient Richardson number (Ri), the turbulent Froude number (FrT), and the buoyancy Reynolds number (Reb) are …

Coastal Defenses, U.S., Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Provides an overview of U.S. military coastal defenses during the period up to and including the War 1812.

An Emerging Vocabulary: Architecture Of Performance, Jeremy H. Stock

Kaleidoscope

Re-chartered at the University of Kentucky in 2005, the Triangle Fraternity – a brotherhood of students studying Architecture, Engineering, and Sciences – now seeks to establish a visible presence by building a new fraternity house on-campus. To enable this investigation, professors Gregory Luhan, Peyman Jahed, and Bruce Walcott developed a design + energy studio experience that provided a framework for an integrated design team to use a systems-thinking approach to generate a range of scalable, net-zero energy prototypes. These prototypes can be applied in a variety of contexts and have the potential to address larger issues, such as energy efficiency …

No Admixture, Sustainable, Self-Consolidating Grout, Craig Baltimore, James P. Mwangi, Eric W. Bateman

Architectural Engineering

The consolidation of grout in concrete masonry unit (CMU) walls is labor-intensive. Also, the grout’s Portland cement content has a high embodied energy demand – a non-sustainable characteristic. For the labor-intensive issue, chemical admixture self-consolidating grouts have been used in walls 12.67 ft. (3.86 m) tall, however the chemical additive can impose new limitations on the grout (non-robust characteristics). No admixture self-consolidating grout with high percentage Portland cement replacement have potential for robust and sustainable application. This paper reports on the consolidation of no admixture self-consolidating grout made by substituting high percentages of Portland cement with Type-F fly ash and/or …

Determining Annoyance Thresholds Of Tones In Noise, Jennifer M. Francis, Joonhee Lee, Lily M. Wang

Durham School of Architectural Engineering and Construction: Faculty Publications

Building services equipment often produces noise signatures with significant tones in them that can lead to complaints in the built environment. Previous studies have investigated prominence levels of assorted tonal frequencies, but it is still unclear what prominence of the tones across varying tonal frequencies can lead to human annoyance. This project seeks to apply two different methods towards defining annoyance thresholds of tones in noise at two tonal frequencies: 125 Hz and 500 Hz. In the first, subjects are asked to perform a task, while exposed to ten minutes of a broadband noise spectrum with a specific level of …

Using K’Nex To Teach Large Scale Structures To Architects And Constructionstudents, Allen C. Estes, Craig Baltimore

Architectural Engineering

The College of Architecture and Environmental Design at California Polytechnic State University in San Luis Obispo (Cal Poly SLO) is the only college in the nation that includes architecture (ARCH), architectural engineering (ARCE) and construction management (CM) programs in the same college. Given the unique mix of disciplines and the emphasis on interdisciplinary collaboration, the ARCH and CM students take a five-course structural engineering sequence from the ARCE department. A challenge of these courses is to maintain some degree of computational rigor while offering a broader perspective that will benefit the ARCH and CM students. This paper reports on one …

New Civil Engineering Program Criteria: How The Sausage Is Being Made, Allen Estes, Thomas A. Lenox

Architectural Engineering

The American Society of Civil Engineers organized the Civil Engineering Program Criteria Task Committee in October 2012 whose charge is to determine if the current ABET Civil Engineering Program Criteria (CEPC) should be changed to reflect one or more of the 24 outcomes of the second edition of the Civil Engineering Body of Knowledge published in 2008. After over a year of conference calls and face to face meetings, the committee has drafted and disseminated a proposed CEPC. This paper chronicles the development of the proposed criteria by sharing a review of the literature, the committee’s methodology and process, the …

Water Recycling In Green Buildings: Grey Water Treatment And Reuse Benefits In Al-Wagan Residential Neighborhood In Al-Ain City, Al Dehaim Nassib Suhail Yatba Al Ameri

Theses

Water scarcity is a worldwide problem that called for a wiser and more sustainable resources' management. Grey waste water treatment is considered a widely spread technology that dominates water management in order to substitute the potential deficiencies.

Water use in the last three decades in the UAE has witnessed both a great increase and pressure on groundwater and desalinated water. This consequently has called for continuous, serious and diversified efforts to simultaneously improve the supply and sustain the water use by treatment and recycling. Besides UAE's natural population growth, the demand for water is also expected to increase significantly in …

Structural Damage Detection Utilizing Experimental Mode Shapes, Evan Jamison Gerbo

Master's Theses

A method of locating structural damage is developed and tested to aid in the evaluation of structural health. This method will help minimize the cost of structural inspection and repair by informing engineers of where damage, due a seismic event, has occurred before the removal of finishes for visual inspection. This thesis begins to answer the question “can structural damage be detected solely through analysis of experimentally measured mode shapes?”

The work encompasses construction of a test structure, with three braces that can be repeatedly engaged or dis-engaged, thus allowing for testing of a variety of braced configurations. For this …

Effects Of Polyethylene Terephthalate Fibers In The Water Resistance Of Compressed Stabilized Earth Blocks., Ebrima Colley

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

This research project focuses on investigating the effects of synthetic fibers (PET) and amount of cement stabilization on the water absorption, water surface erosion, and wet compressive strength of the compressed stabilized earth blocks (CSEB). The use of locally available soils blended with fibers and cement was investigated to obtain a design mix for compressed stabilized earth blocks capable of staying intact in wet and humid regions in the world (i.e. regions with annual rainfall of over 50 in). Blocks with varying cement percentages of 5, 8, 10, and 15% by weight were produced with 3 specimens each, with and …

Energy Benefits Of Different Dedicated Outdoor Air Systems Configurations In Various Climates, Shihan Deng

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

Dedicated Outdoor Air Systems (DOAS) are proven to be beneficial in many practices. However, not all DOAS configurations under different climates provide the same benefits. This study presents a simulation on evaluating various energy saving benefits of different DOAS configurations among diverse climate zones of commercial buildings in the United States.

Three DOAS configurations in a medium office building are simulated in this study: (1) fan-coil units (FCUs) as terminal units with a DOAS unit supplying conditioned outdoor air (OA) to each FCU intake; (2) FCUs with a DOAS unit supplying conditioned OA directly to each occupied space; and (3) …

On A Combined Adaptive Tetrahedral Tracing And Edge Diffraction Model, Carl R. Hart

Durham School of Architectural Engineering and Construction: Dissertations, Theses, and Student Research

A major challenge in architectural acoustics is the unification of diffraction models and geometric acoustics. For example, geometric acoustics is insufficient to quantify the scattering characteristics of acoustic diffusors. One method of quantifying the scattering characteristics of acoustic diffusers is through computational prediction, typically via the time-independent boundary element method (BEM). In contrast, time-domain computations are of interest for characterizing both the spatial and temporal scattering characteristics of acoustic diffusors. Hence, a method is sought that predicts acoustic scattering in the time-domain. A prediction method, which combines an advanced image source method and an edge diffraction model, is investigated for …

Effects Of Tendon Spacing On In-Plane Behavior Of Posttensioned Masonry Walls, Dongun Ryu, Anil C. Wijeyewickrema, Mohamed A. Elgawady, M. A.K.M. Madurapperuma

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

In-plane behavior of unbonded posttensioned clay brick masonry walls are investigated using detailed finite-element (FE) models. FE models of three walls having different aspect ratios of 1.50, 1.00, and 0.67 are developed. Effects of tendon spacing on in-plane behavior of these walls are investigated using different tendon spacings ranging from 0.61 m (2 ft) to 3.81 m (12.5 ft). In addition, the effects of having different horizontal reinforcement ratios of 0%, 0.1%, and 0.5% on the in-plane behavior of the walls were investigated. The stresses in the tendons are calculated using different approaches, and then the flexural strength of each …

A Unifying Framework For Parameterizing Stably Stratified Shear-Flow Turbulence, Benjamin D. Mater, Subhas Karan Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

An alternative framework for parameterizing stably stratified shear-flow turbulence is presented. Using dimensional analysis, four non-dimensional parameters of interest are identified that consider the independent effects of stratification, shear, viscosity, and scalar diffusivity. In the interest of geophysical applications, the problem is further simplified by considering only high Reynolds number flow. This leads to a two-dimensional parameter space based on a buoyancy strength parameter (i.e., an inverse Froude number) and a shear strength parameter. Consideration for the gradient Richardson number allows the space to be divided into an unforced regime, a shear dominated regime, and a buoyancy-dominated regime. On this …

Building And Maintaining Plankhouses At Two Villages On The Southern Northwest Coast Of North America, Emily Evelyn Shepard

Dissertations and Theses

Plankhouses were functionally and symbolically integral to Northwest Coast societies, as much of economic and social life was predicated on these dwellings. This thesis investigates both plankhouse architecture and the production of these dwellings. Studying plankhouse construction and maintenance provides information regarding everyday labor, landscape use outside of villages, organization of complex tasks, and resource management.

This thesis investigates three plankhouse structures at two sites, Meier and Cathlapotle, in the Lower Columbia River Region of the southern Northwest Coast of North America. Methods consisted of digitizing over 1,100 architectural features, creating detailed maps of architectural features, and conducting statistical and …